Mark, I knew the spellings of all but one of those "B" words. I thought the valkyrie's name was spelled with only one N, not two. Thanks to good ol' Wikipedia, I discovered that the original name of Brünnhilde in Norse mythology is Brynhildr -- which looks more like a line on an eye chart:

https://en.wikipedia.org/wiki/Brynhildr

Now -- is "bathyscaph" a misspelling? The deep-sea submersible vehicle known as a bathyscaphe was invented by Auguste Piccard. The first one was constructed in 1946-48. The name comes from the Greek bathys ("deep") and skaphos ("vessel; ship"). I consulted several dictionaries and websites and can find no source which gives the spelling as "bathyscaph." On the Oxford English Dictionary site, I got this message:

"No exact match found for 'bathyscaph' in US English. Did you mean 'bathyscaphe'?"

"Technically correct." Indeed. The Dictionary.com website, which uses the Random House Dictionary, lists "bathyscaph" and "bathyscape" as variations of "bathyscaphe." Now I know the spelling in the puzzle is not a mistak. ;)